Improvement in condensing steam-engines



2 Sheets--Sheet 1.

. EDWARDS.

T CONDENSING STEAM ENGINE.

Patented Apr. 25, 1871.

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l. A:l: Sheets`Sheet 2. T. EDWARDS.

'GODENSING STEAM ENGINE.

Patentempr. 25, 1871-.

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dtidi tdrt THOMAS EDWARDS, OF LADYWOOD, BIRMINGHAM, ENGLAND.

Letters Patent No. 113,989, dated April 25, 1871.

IMPROVEMENT IN CONDENSING STEAM-ENGINES.

The Schedule :efe-ned to in these Letters Patent and making past of the lame.

To all to whom 'it (may concern Be it known that I, THOMAS EDWARDS, of Ladywood Birmingham, in the county of Warwick, England, engineer, a subject of 'the Queen of Great Britain, have invented or discovered new and useful Improvements in Condensing Steam-.Engines and I, the said THOMAS EDWARDS, do hereby declare the nature o'f the said invention, and in what manner the same is to be performed, to be particularly described and v ascertained in and by the following statement thereof that is to say- Ihis invention has for its object improvements in condensing steam-engines. p

At the present time, in condensing steam-engines the steam from the steam-cylinder is passed into a c'lose vessel called the condenser, which is kept cool by means of cold water, and in whicha partial vacuum is maintained by an air-pump provided for the purpose.

According to my invention Iv employ no separate air-pump, but I maintain a .sudcicnt vacuum in the condensing-vessel by a piston workingrwithin it. I also supply steam over and under this piston in quantity suicient to give the required motion to the piston, and also to aid the engine.

The arrangement I employ is` as follows:

The condenser is a cylinder with a piston working within it suitably coupled with the main shaft of the engine and working in unison with the main steampiston. The piston of the condenser being, say, at thetop of the stroke, steam is admitted over it to cause its return. The steam is soon cnt oli', and when the piston has arrived nearly at the bottom of the cylinder a shower of cold water is thrown into 'the space over the piston to condense th`e highly-attenuated steam which this space then contains. When the piston is at the bottom ofthe condenser-cylinder the steam from the steaxn-cylinder, and which isrequired to be condensed, is admitted to the space over the piston which remainsopen to it during the next 11p-stroke of the piston, and so, during the up-stroke, a partial vacuum is maintained over the piston. When nearly at the top of the stroke the valve admitting steam from thc engine closes, and the piston forces out oi' the condenser-cylinder the condensation and condensed water, and this water is led away in any convenient manner. Meanwhile, beneath the piston, as it gets to the bottom of the stroke, steam is admitted beneath it just as previously on its upper side. Its first action is to sweep out any remaining air and water from beneath the piston, and then, the'escape-passage closing, itiacts to force up the piston, and as it ascends the steam from the steam-cylinder is condensed in the space above it, as before stated.

The action on the one side of the piston is in all respects similar to that on the other side, and so at every stroke of the engine the work goes on.

The steam which is used for giving motion to the piston in the condenser-cylinder and for sweeping out the remaining air and water from the condenser may be boiler-steam, or it may be exhausted' steam. from the steam-cylinder.

The condensing arrangements above described may be used as a power-engine without being combined with a steam-cylinder or cylinders as above stated.

In order that my said invention may be most fully understood and readily carried into effect, I will proceed to describe the drawing hereunto annexed.

Description of theDrawtug. The vdrawing represents condensing apparatus adapted to receive' and condense steam after it has worked in a steam-engine cylinder.

a a is the condenser-cylinder. Its cubic contents should be about one thousand cubic inches per horse-vv ele are similar valves to admit steam (by'preference boiler steam) for a short time at the beginning of each stroke to blow the water out of the condenser-cylinder and destroy the vacuum acting against the piston.

ff are slide-valves, `opening to allow of the lexpulsion of the water from the condenser-cylinder andthen immediately closing.

g g are valves opening to admit cold water into the condenser-cylinder to condense the steam.

The valves d d, e e, and f f are controlled by cams on the axes t h, which are so geared as to rotate at the samespeed as the main shaft of the engine.

AThe axis -i is also rotated at the same speed, and, by an eccentric, opens the injection-valves g and g'.

Ihe valve g admits the water over a perforated plate at the top of the cylinder, and the valve g up a sliding pipe, b', into the piston b and over the perforated plate b* which forms the bottom of the piston.

The drawing represents the condenser-piston at the bottom of its stroke, aud the piston in the steam-cylinder will be in a similar position. At this time, as will be seen, the exhaust-valve d from the upper part time longer.

During the earlier part of the lip-stroke the upper injection-valve .7 remains open and a shower of. water is discharged by it into the upper part of the cylinder, condensing the steam, which is at the same time entering from the steam-cylinder, and after the valve closes the shower will continue for au instant, until the cavity over the perforated plate is empty.

When the piston in the condenser-cylinder has made the greater part of its upward stroke the lower injection-valve g opens and prepares avaeuum under the piston ready to receive the steam from the lower part of' the steam-cylinder as .soon as the lower` exhaustvalve al opens, which it does as the piston in the condenser approaches the top of the stroke.

The. upper escape-valvef opens just before the piston reaches the top of the cylinder; and if the quantity of water in the condenser-cylinder is such that a pressure comes upon the valve before it opens it is able to leave its seat and permit the'water to pass.

At the return of the condenser-piston the course of the stroke is similar, as already stated.

In place of admitting boiler-steam to the condensercylinder itis, in the case of compound engines, advantageous to use the steam issuing frorn thevhlgh-press- 'ure cylinder. l

In place of admitting a shower of condensing water into the .condenser-cylinder' this cylinder may be cou' vpled with a surface condensing-chamber, the arrange- Vejected in the manner-already described. Having thus described the nature of my said invention-and the manner of performing the saine,

I would have it understood that whatI claim is 1. The condensing apparatus, composed of the coudenser-cylinder, the piston thereof, the water-entry valves, the water-escape valves, andthe steam-entry valves for the entrance of exhaust steam from the steam-cylinder. all combned substantially as before set forth.

2. The combination of the condenser-cylinder, the

.piston thereof, the water-entry valves, the water-escape valves, the steam-entry valves for the admission oi' exhaust steam, and the steam-entry valves for the admission of steam to displace the air, substantially as before set forth.

3. The general arrangement of the apparatus, substantially as described.

fitnesses THOMAS EDWARDS.

Gno. U. S. Comma, 

